Improvement in methods of and apparatus for drying



Y 2Sheets- 'Sheet;1. 'Gn F. WILSON & C. A. CATLI Method of and Apparatusfor Drying.-

No. 215.191. Patented May 6,179.

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N,PEI'ERS. PNOTovLITMoGFuPHER. WASHINGTON. u C.

Patented May 6,1879.

ILPTERS. PHUTOfLlTHQBHAFHER. WASHINGTON. D C.

u 2 sheetssheet 2. G. P. WILSON & C. A. CATLI'N. Method of and Apparatusfor Drying. 215,191.

VNITEJJ STATES PATENT OFFICE GEORGE F. WILSON, OF EAST PROVIDENCE, ANDCHARLES A. CATLIN, OF

PROVIDENCE, RHODE ISLAND. r

IMPROVEMENT IN METHODS OF -AND APPARATUS FOR DRYING.

Specification forming part of Letters Patent No. 215,191, dated May 6,1879; application iiled February 21, 1879.

To all whom it may concern.- v

Be it known that we, GEORGE F. WILSON, of East Providence, in the Stateof Rhode Island, and oCHARLEs A. CATLIN, of Providence, in said State,have invented a new and useful improvement in methods of and apparatusfor drying various substances to be used in chemical works and otherindustrial establishments, which improvement is fully set forth in thefollowing specification.

The invention consists in the method of drying substances of variouskinds, and also in the construction and combination of parts of theapparatus employed, as hereinafter set forth.

The material to be dried is subjected, by means of a series of endlessaprons on which it is exposed, to the action of a blast of air moving inopposite direction to the movement of the material to be dried on theaprons, the air-blast being dried by Ichemical means (sulphuric acid) ina dehydrator of special construction, and heated or cooled by passingover aicoil of pipes, through which a suitable heating or cooling medium(steam or hot or cold water) is circulated.

The following description will enable those skilled in the art to whichit appertains to make and use my said invention, reference being had tothe `accompanying drawings, which form a part of this specification.

Figure l represents a side view, partly in section, of the apparatusemployed, by me; Fig. 2, a top or plan view; Fig. 3,` an end view,showing the upper part of the drying-chamber, a portion of the casingbeing removed; Fig. 4, an enlarged view, partly in section, illustratingthe construction of the dehydrator; Figs. 5 and, side and top views,respectively, showing, on a large scale, the manner of forming andoperating the endless apron.

A is the drying-chamber; B B1, the endless aprons, supported by rollersB2, turning in bearings, and revolved in opposite directions by thebevel-gears' B3 B4, attached thereto and on the upright shafts B5 andBG. These shafts are operated, -through bevel-gears B"I B8, by means ofa pulley on the shaft B9, rotated by suitable power. Scrapers B10 may beprovided on the under side of each apron to prevent adherence of thematerial thereto. C is the air heating or cooling chamber, provided witha coil or coils of pipe, C1, through which a suitable heating or coolingmedium is introduced by the connecting-pipes C2, provided withstop-cocks, as shown in Fig. l.

Any desired medium may `be used-steam or hot or cold water, or otheriluid of the proper temperature. l

The dehydrator, or apparatus for depriving the air of moisture before itis passed through the chamber C, is denoted by D. The outer or inclosingvessel is made of lead, the sides being extended upward and outwardabove the top to' form a receptacle, D1. The interior of the dehydratoris divided by glass plates or partitions D2, keptin place by leadencross-bars D3, which latter do not make a close joint with the glassplates and sides of the vessel, but sufficient space is allowed betweenthem for a liquid placed in the receptacle Dl to trickle down over theinterior of the dehydrator and sides of the said plates in a thin lilm.

The dehydrator, instead of being made of lead, might be lead-lined; orit may be made,

together with the partitions and cross-bars, of any desired materialcapable of resisting the corrosive action of the drying material used,which is preferably sulphuric acid. A suitable fan, E, or other kind of,blowing apparatus, is used to create the proper current of air. rEheoutlet of the blowenis connected by the passage or channel El with thedehydrator. The latter is in communication with the heating or coolingchamber through the short passage E2, and the heating or cooling chambercommunicates with the drying-chamber by the opening E3 at the bottom.E4L is the passage for the escape of the air from the drying-chamber.

F is the hopper for introducing the material to be dried, and F theopening at which the dried material is removed from the drying-chamber.

The endless aprons B B1 are constructed in the following way: The sidesare formed by chains b of links b1, each link being rectangular, andconnected with the neXt one by a hook, b2, formed in one piece with orWelded or otherwise fastened to the bodyof the link. Each link isprovided on one side with a projection, b3, welded to or formed in onepiece with the link, and having a number of holes formed therein.

The rollers B2 are provided at the ends with wheels b4, fixed on theshaft by afeather, or in other suitable way. Projections b5 ou thesewheels t within the rectangular portions of the links b, and cause therevolution. The fabric, c, of which the endless apron is composed isfastened to the projections b3 of the links bl by a cord or lacing, asclearly shown in Fig. 6.

The operation or" the machine is as follows: Sulphuric acid is placed inthe receptacle Dl on the top of the dehydrator D. Steam or hot or coldwater is passed through the coil of pipes G1 in the chamber C. The fan Eis rapidly revolved. The endless aprons B B1 are revolved by theirgearing. The material to be dried is introduced b v the hopper F anddelivered on the upper apron, B, which carries it to the opposite sideotl the drying-chamber and deposits it on the next apron, Bl, whichcarries it back to the iirst side oi' the dryingchamber and deposits iton the next apron. The air forced by the fan E passes through thedehydrator D, where it is dried by contact with the sulphuric acid,which trickles from the receptacle D' down the sides of the glass platesD2; thence it passes through the chain' ber C, where its temperature 1sraised or lowered, according to the temperature ofthe medium circulatingin the pipe-coil C, and, entering the drying-chamber, acts upon thematerial exposed ou the apron.

On the drawings, the direction of the airblast, the direction oi' themovement ot' the endless aprons and material dried, and also of partofthe gearing are shown by arrows.

The invention may be employed for drying glue, acid-powders, or creamtartar substitutes, grain, or other articles, and it is, among otheruses, adapted for the production of des ccated milk or milk-powder.

The fabric ot' whichthe endless aprons are composed may be of anydesired material; but when the apparatus is used in making desiccatedmilk the fabric employed should be such as to have uo injurious actionthereupon, and to impart no disagreeable navor thereto.

Instead of sulphurlc acid, an equivalent hygroscopic liquid-dryin gmaterial might he used. The sulphuric acid is believed also to have anadditional purifying eect on the air by the destruction ot' germscarried thereby.

Having thus described our said invention, and the manner in which thesame is or may be carried into effect, what we claim, and desire tosecure by Letters Patent, is-

1. The method ot drying or depriving substances of moisture by exposingthe same to a blast of air which has been deprived of its moisture bypassing in contact with a hygro scopic liquid in thin tilms, and thenregulated as to its temperature by passing over a coil in which aheating or cooling medium is circnlated, substantially as described.

2. The method oi' drying substances by exposing the same successivelyupon a series of endless aprons to a blast of air moving in oppositedirections to the movement of the substance to be dried on the aprons,the said airblast being deprived of its moisture by passing in contactwith a hygroscopic liquid in thin films, and regulated as. to itstemperature by passing over a coil of pipes in which a heating orcooling medium is circulated, substantially as described.

3. The method of preparing air for use in drying apparatus, the sameconsisting in passing it in contact with sulphuric acid in thin films,substantially as described.

4. The combination of the following elements: iii-st, a drying-chamberprovided with a series of endless aprons and means for operatingalternate ones in opposite directions; second, a cooling or heatingchamber provided with a coil for the circulation of a suitable medium;third, a dehydrator; and, fourth, a fanblower, substantially asdescribed.

5. An endless apron formed of a fabric stretched between and secured atthe sides to endless chains composed of links, each provided with a hookat one end, attached to or formed in one piece therewith, substantiallyas set forth.

6. A dehydrator havingits interior divided by partition-plates kept inplace by cross-bars, and having its sides extended upward above the topto form a receptacle, a slight space being left between aforesaidcross-hars and plates to allow the flowing between them ot' the liquidplaced in said receptacle in thin films, substantially as described.

7. A dehydrator for use with sulphuric acid, the same consisting of theleaden inclosingcasing and acid-receptacle on top thereof, the glasspartition-plates, and leaden cross-bars, substantially as described.

In testimony whereof we have signed this specification in the presenceof two subscribing witnesses.

GEO. F. WILSON. OHAS. A. GATLIN. Witnesses to signature ot' Geo. F.Wilson:

A. POLLQK, E. A.D1ox. Witnesses to signature of C. A. Catlin:

E. J. CARPENTER, G. M. CARPENTER, Jr. i

